Plate-developing holder.



L. F. LIBBY.

PLATE DEVELOPING HOLDER. APPLICATION FILED MAR. 21, 1916.

3223,057. Patented Apr. 17, 1917.

LEONARD F. LIBLBY, OF PORTLAND, MAINE.

PLATE-DEVELOPING HOLDER.

Specification of Letters Patent.

Patented Apr. 17, 1917.

Application filed March 21, 1916. Serial No. 85,714.

To all whom it may concern:

Be it known that I, LEONARD F. LIBBY, a citizen of the United States, residing at Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Plate-Developing Holders, of which the following is a specification.

This invention relates to improvements in plate developing holders. Among other objects it is designed to provide a device which can be readily attached to and removed from the plate, which is, when the plate is supported in the holder, spaced apart from the surface of the plate at all points and which is provided with means for supporting the plate in the bath.

In the drawings herewith accompanying and making a part of this application F igure 1 is an elevation of my improved device and Fig. 2 is an edge view of the same.

Same reference characters indicate like parts in the several figures.

In said drawings 1 represents a glass negative plate of the kind in general use by photographers. These plates are usually immersed in a bath for developing purposes. Applicants device for suspending the plate consists of a flexible wire spring 2 which may be conveniently formed substantially top-shaped, the wire having formed therein by bending hooks 3, one at the bottom and one at each side, adapted to engage the bottom and side edges of the plate. These hooks may be bent, away from the plane of the body of the wire, as seen at -l, so that the wire will, when the plate is in position, be spaced apart from the sensitive face of the plate at all points. Preferably the normal width of the holder is somewhat less than the width of the plate, so that the plate is held by the holder under yielding tension. The ends of the wire are brought together preferably above the plate and terminate in the hook 5 by which the plate is adapted to be supported in the bath. If desired the ends of the wire may be bent in the lane of the body laterally, to points exten ing beyond the edges of the plate as seen at 6, whereby the ends may rest upon the walls of the bath tank to support the plate.

Copies of this patent may be obtained for The operation of my improved holder is as follows:

The plate after being exposed is placed in the holder in engagement with the bottom and one side hook. The holder is then pressed downwardly expanding the sides of the holder laterally until the plate can pass by the hook on the other side of the holder. The holder is then released and at once returns to its normal position thus engagin and retaining the plate at three points and holding it securely in position. The plate is released from the holder by expanding the holder as before.

It will be evident that the holder may be variously shaped and may have more than three hooks. The plate holding hooks may be formed in different ways and the holder supporter may be formed in various ways and still be within the spirit and scope of my invention. It will be noted that the holder herewith shown and described is made of a single piece of wire formed by bending it to the desired structure. While this is the preferable method of forming the holder, applicant does not wish to be limited to a one piece structure.

I claim:

1. A developing plate holder comprising a spring body provided at the bottom and sides with hooks adapted to engage the bottom and side edges of the plate and means for suspending the holder in the bath.

2. A developing plate holder comprising a spring body provided at the bottom and sides with hooks formed integral therewith and adapted to engage the bottom and side edges of the plate and means for suspending the plate holder in the bath.

3. A developing plate holder comprising a spring body provided at the bottom and sides with hooks offset out of the plane of the body adapted to engage the bottom and side edges of the plate, whereby the hooks are spaced apart from the plate at all points when in position, and means for supporting the holder in the bath.

In testimony whereof I affix my signature.

LEONARD F. LIBBY.

five cents each, by addressing the Commissioner 0! Patents, Washington, D. G. 

